Previous studies supported by this grant have resulted in the isolation of several molecules from bovine connective tissue, particularly the aorta. These include a proteoglycan and a protease inhibitor from aorta, a second protease inhibitor from cartilage, and lysozyme. We now wish to study the interactions between these molecules or any additional proteoglycans we succeed in isolating and each other, other components of vascular walls, and components of the circulating blood. This would initially be done on using in vitro systems in which the effects of such molecules on platelet aggregation, the compliment system, and the clotting cascade as well as interactions with lipoproteins and minerals would be studied. The question of whether aggregation and disaggregation of arterial proteoglycans affects these interactions will also be assessed. Attempts to determine the locus of these molecules will be made using immunocytochemical techniques.